| Message ID | d5b487b58c2c6b3e68de0e858b84877434f05c76.1496843678.git.jcody@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 06/07/2017 08:55 AM, Jeff Cody wrote: > In external_snapshot_abort(), we try to undo what was done in > external_snapshot_prepare() calling bdrv_replace_node() to swap the > nodes back. However, we receive a permissions error as writers are > blocked on the old node, which is now the new node backing file. > > An easy fix (initially suggested by Kevin Wolf) is to call > bdrv_set_backing_hd() on the new node, to set the backing node to NULL. > > Signed-off-by: Jeff Cody <jcody@redhat.com> > --- > blockdev.c | 4 ++++ > 1 file changed, 4 insertions(+) > Reviewed-by: Eric Blake <eblake@redhat.com> > diff --git a/blockdev.c b/blockdev.c > index 892d768..6472548 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -1803,7 +1803,11 @@ static void external_snapshot_abort(BlkActionState *common) > DO_UPCAST(ExternalSnapshotState, common, common); > if (state->new_bs) { > if (state->overlay_appended) { > + bdrv_ref(state->old_bs); /* we can't let bdrv_set_backind_hd() > + close state->old_bs; we need it */ > + bdrv_set_backing_hd(state->new_bs, NULL, &error_abort); > bdrv_replace_node(state->new_bs, state->old_bs, &error_abort); > + bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */ > } > } > } >
Am 07.06.2017 um 15:55 hat Jeff Cody geschrieben: > In external_snapshot_abort(), we try to undo what was done in > external_snapshot_prepare() calling bdrv_replace_node() to swap the > nodes back. However, we receive a permissions error as writers are > blocked on the old node, which is now the new node backing file. > > An easy fix (initially suggested by Kevin Wolf) is to call > bdrv_set_backing_hd() on the new node, to set the backing node to NULL. > > Signed-off-by: Jeff Cody <jcody@redhat.com> Thanks, applied to the block branch. Kevin
diff --git a/blockdev.c b/blockdev.c index 892d768..6472548 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1803,7 +1803,11 @@ static void external_snapshot_abort(BlkActionState *common) DO_UPCAST(ExternalSnapshotState, common, common); if (state->new_bs) { if (state->overlay_appended) { + bdrv_ref(state->old_bs); /* we can't let bdrv_set_backind_hd() + close state->old_bs; we need it */ + bdrv_set_backing_hd(state->new_bs, NULL, &error_abort); bdrv_replace_node(state->new_bs, state->old_bs, &error_abort); + bdrv_unref(state->old_bs); /* bdrv_replace_node() ref'ed old_bs */ } } }
In external_snapshot_abort(), we try to undo what was done in external_snapshot_prepare() calling bdrv_replace_node() to swap the nodes back. However, we receive a permissions error as writers are blocked on the old node, which is now the new node backing file. An easy fix (initially suggested by Kevin Wolf) is to call bdrv_set_backing_hd() on the new node, to set the backing node to NULL. Signed-off-by: Jeff Cody <jcody@redhat.com> --- blockdev.c | 4 ++++ 1 file changed, 4 insertions(+)